Notebook of James Stuart Leslie Ross - Part 9

General Flying 13-7-17.

Lecture I

Cleaning. Parts to be kept clean on an

aeroplane:-

All Fabric, (Planes, Fuselage)

Never use petrol to clean fabric,

as it has a detrimental effect,

on dope & fabric

Greasing. Parts to be greased:-

All controls, turnbuckles, pulleys,

care to be taken that grease does

not come into contact with fabric

Painting Parts to be painted:-

All metals part struts or king

posts, or any parts that are likely

to rust.

Examination Points to look to:-

See that all turnbuckles are locked

All bolts must be split-pinned &

pins turned over.

Control Wires.

See that there is no fraying,

especially where wire goes over

pulley.

 

If forced landing is made & a stay

for some time is necessary, face

machine into wind & peg down

securely.

Inspection. Inspect all splices, tyres,

x under-carriage & tail skid.

See that all instruments are

O.K Examine rubber joints in

Air Speed Indicator tube

See that adjustable Aneroid Dial

is on O before going up.

General Flying      Lec 2. 20.7.17

Don'ts 

Dont fail to test controls.

   "     forget to switch off

   "         "      "   test engine

   "     take machine into air with

erratic Revs.

   "     taxi clear of sheds until

"all clear" signal given

   "     take off unless dead into

wind.

   "     baulk machines landing

   "     Stall.

   "     Choke engine getting off

   "      lose engine.

   "      circuit the wrong way

(Red flag right, blue flag left).

   "     depend on T

   "      turn without banking.

   "      forget that machine is frail

   "          "        "   the speed is greater

than it seems.

Theory of Flight      28.7.17

Flight is secured by driving a surface

up thro air upwards & towards

direction of flight.

Depends on.

(I) Forward Motion

(2) Size & Shape of Surface

(3) Angle of Incidence

Reaction caused by driving thro'

air.

R=KS V² i

R = Reaction

K = A constant found by experiment

S    Surface in Sq metres

V    Velocity

i      Is angle of incidence measured

in radians.

If speed is doubled, reaction of on

planes is 4 times as much as before.

 

Flat  Surface

Hand drawn diagram - see original document

 

Hand drawn diagram - see original document

Drift is of 3 types -

1. Active Drift.

2. Passive Drift caused by all portions

of aeroplane, other than planes.

3 Skin Friction due to bad

doping or loose fabric.

Lift/Drift Ratio expresses efficiency of

machine.

Streamlining means reduction of passive

drift.

The greater the velocity the less

Angle of incidence.

Greater climb, greater angle

of incidence.

Camber is to reduce drift (by easing

off the passage of air).

Aspect Ratio is the proportion of

span to chord

Stagger To eliminate interference without

stagger. Gap to be 1½ times Chord.

(Long struts & wires would introduce

passive drift).

Theory of Flight       28.7.17

Lift varies as Horizontal Equivalent

varies.

Hand drawn diagram - see original document

Margin of Power is the power available over

that necessary to maintain horizontal

flight.

Margin of Lift the height a plane can attain

in given time from a given altitude

Minimum Angle of Incidence - the lowest

angle at which flight can be

maintained.

Maximum Angle of Incidence is greatest

angle at which flight can be

maintained

Optimum Angle of Incidence - angle at

which lift-drift ratio is highest

Best Climbing Angle - best climbing angle

approx ½ way between the optimum

& maximum.

 

30.7.17

Hand drawn diagram - see original document

Position of flares for night landing

(Short end of L facing wind).

Red lights placed at each extremity

of aerodrome.

Hand drawn diagram - see original document

Stability tendency of an object to

return to its original position

if disturbed by outside elements

Unstable moves further away from

original position.

Long Stability secured by setting tail

plane at a lesser angle than main

planes

Theory of Flight   30.7.17

Longitudinal Dihedral - the angle

between tail plane & main 

planes

 

 

Compass. Lec. I   15.7.17.

Elementary Magnetism

Of the cause of causes of magnetism

little is known. It is an attractive

& repulsive force, not a propulsive

force. In explanation of this

difference, the lines of a railway direct 

the engine to its destination, but do

not propel it.

Magnetism is almost entirely

superficial. There is very little

penetration of a magnetised substance.

A steel tube can be as highly

saturated with magnetism as a solid

rod of the same dimensions.

A magnet may be defined as an object

which if freely suspended by its

centre of gravity, will point

towards the Magnetic Pole.

All magnets have two poles. If

a mag. be broken into 2 or more

pieces, each piece will become a

perfect magnet with 2 poles. These

 

 

poles, or ends, are known as the

North Seeking End & the South

Seeking end.

The World itself is a huge

magnet with its 2 Magnetic Poles.

In common with all other magnets

these poles exert a force which

is equal but opposite.

it is the World's magnetic force

which directs a magnetised Compass

needle to the Magnetic Pole.

By Convention, the magnetism of

the North Magnetic Pole is called

Blue Magnetism & that of the

South magnetic Pole, Red

magnetism. Therefore the North

Seeking End of a magnet is

often coloured Red & the 

South Seeking end, Blue.

Like poles repel each other & unlike

poles attract. So it follows that

the Blue Magnetism of the North

Magnetic Pole attracts the Red

or north Seeking End of a freely

Compass Lec I      15.7-17

suspended magnetic needle, while

the Red magnetism of the South M.P.

attracts the Blue or Sth Seeking End

of needle.

Magnetisable Substances, Steel

Hard Iron & Nickel. (Nickel-steel

is non-magnetic). These retain

magnetism permanently. Only

become demagnetised by concussion

or overheating.

Substances capable of being

magnetised may be rendered

magnetic in following ways :-

(1) By Percussion such as hammering

(2) By Electricity :- a piece of steel,

hard iron or nickel placed inside

a helical coil of wire thro' which

an electric current is passed, becomes

magnetised.

3. by stroking with a magnet

4. by the action of an electromagnet.

An Elec. Mag. is a coil of wire closely

bound round a horse-shoe shaped piece

 

of soft iron. The passage of the elec.

current magnetises this core, which

magnetises any steel, hard iron or nickel

placed within its field.

Soft iron is more susceptible to

magnetism than hard iron but

will not retain its magnetism.

it can only become saturated

with Transient magnetism.

The poles of a soft iron object

will vary according to the direction

from which it is being magnetised.

To test whether an object is

magnetic or not, find whether

another mag. will repel it. Any

piece of Steel or iron will be

attracted by a mag. of suff. Power.

But for Repulsion it is necessary

that the object be magnetised itself

& so possessing 2 poles.

Position of North Mag. Pole

does not correspond with True or 

Geog. N. Pole. It is supposed to

move elliptically round the True

Compass Lec I    15-7-17.

North. It is now moving slowly

Eastward. It is situated over 1000

miles South of the true pole, to

the westward of it, so the Magnetic

Meridian does not correspond with

the Geog. Meridian. The 2 Meridians

drawn from Greenwich contain an

angle of 15°. This is Known as

Mag. Variation.

The force exercised by Magnetism

has 2 Components - a Horizontal &

a Vertical but as in the manuf. of

compasses the vert. component is

compensated for mechanically. It

is not necessary to deal with these

components in a brief treatise

devoted to Elem. Magnetism.

All Compasses work on

exactly the same principle,

no matter how they may vary in

construction. With the exception

of the magnetised needles all parts

of a compass are non-magnetic.

 

such as brass, aluminium, bronze &
white metal.
parts:-
The Box  or in the case of the admiralty
pattern, the Containing Ring.
The Corrector Box or Magnet Holder in which
are place the correcting magnets,
which are used to adjust the compass.
The Anti-Vibration Springs & Buffers. The Springs
are of phosphor bronze. The buffers are
of felt or fibre. These are necessy
to lessen the shock on landing &
to deaden the vibration of engine.
They allow bowl of compass & certain
amounts of free play in all
directions.
The Bowl  is filled with distilled water &
alcohol to act as a damper on
the movements of the compass
card & so render it less sensitive
to disturbances by movements of
machine. Also gives buoyancy
to floats, thus reducing its weight
& so reducing friction between
Compass Lec 1
15-7-17
pivot & cup. Alcohol is to prevent
fluid from freezing.
The Expansion Chamber is made of flexible
corrugated metal & expands under
pressure when fluid expands, owing to rise in Temp. & contracts when
fluid contracts. Otherwise the
expanding fluid might break
compass glass.
The Float  is hollow & water tight. The
magnetised Compass needles (generally
two) are soldered inside it. It rests on
The Pivot  which passes thro' float. The
pivot has a point of Iridium
or Agate. It rests on a
Cup  of Sapphire, which is supported on
The Stem.
The Stop or Containing Wire  prevents float
slipping off cup when machine
is banking.
The Card  is fastened to the float. It is
of mica or photo. film. It is
lettered on the 8 points of the Compass.
 

Each marking rep 5°. It is
numbered for every 10° but for sake
of clearness the cypher 0 is
omitted; for example,
E, which is 90° is numbered 9. It is
often painted with radium so that
it may be read in the dark.
Except when momentarily disturbed
by a turn or by engine acceleration,
or retardation, the mag. needles
are continually pointing to the North,
therefore the card, float & needles
are practically a fixture. It is only
the bowl & outer case of Compass
which follow turns of machine.
The Lubber Line  sometimes called the Lubber
point is fixed to the inside of bowl.
It is in the true fore & aft line
of bus & so indicates the direction
in wh. machine is flying.
A Reading of Compass is the register of
the particular degree, marked on the
compass card, which is in line
 with the lubber line